Copying apparatus for sheet originals and thicker originals

ABSTRACT

A copying apparatus for selectively copying sheet originals and thicker originals such as books and the like comprises various process devices as used in an electrophotographic copying apparatus of the type which employs the liquid development and drum type image transfer system. The copying apparatus of the invention includes improvements in such devices as original carriage, original transport apparatus, guide for original carriage, original keep cover, apparatus for controlling the operation of the copying apparatus, apparatus for detecting the amount of toner in developing liquid, copy paper feed apparatus, apparatus for controlling the paper feed apparatus, apparatus for separating copy paper from a photosensitive drum, apparatus for conveying copy paper from the feed apparatus to a discharge port, apparatus for repeating copying operation, apparatus for drying and fixing the image on the copy paper, apparatus for supporting the photosensitive medium, etc.

United States Patent 1191 Komori et al.

1451 Apr. 16, 1974 [22] Filed:

[73] Assignee: Canon Kabushiki Kaisha, Tokyo,

Japan June 1, 1972 [21 Appl. No.: 258,820

[30] Foreign Application Priority Data June 9, 1971 Japan 46-48632 June 3, 1971 Japan 46-38917 June 3, 1971 I Japan 46-38918 June 10, 1971 Japan.... 46-41195 June 10, 1971 Japan..; 46-41196 June 10, 1971 Japan 46-41197 June 21, 1971 Japan.... 46-44611 ug. 30, 1971 Japan 46-66740 [52] US. Cl .1 355/25, 355/3, 355/8, 355/10, 355/11, 355/14, 355/15, 355/27 [51] Int. Cl G03b 27/32, G03b 27/52 [58] Field of Search 355/18, 25, 82, 8

[56] References Cited UNITED STATES PATENTS 6/1971 Murgas.... 355/25 X 3,597,074 8/1971 Murgas 355/25 3,677,635 7/1972 Van Auken et a1. 355/25 X 3,685,905 8/1972 Marshall et al. 355/82 X Primary Examiner-Richard M. Sheer Attorney, Agent, or Firm- Joseph M. Fitzpatrick 5 7 ABSTRACT A copying apparatus for selectively copying sheet originals and thicker originals such as books and the like comprises various process devices as used in an electrophotographic copying apparatus of the type which employs the liquid development and drum type image transfer system. The copying apparatus of the invention includes improvements in such devices'as original carriage, original transport apparatus, guide for original carriage, original keep cover, apparatus for controlling the operation of the copying apparatus, apparatus for detecting the amountof toner in developing liquid, copy paper feed apparatus, apparatus for controlling the paper feed apparatus, apparatus for separating copy paper from a photosensitive drum, apparatus for conveying copy paper from the feed apparatus to a discharge port, apparatus for repeating copying operation, apparatus for drying and fixing the image on the copy paper, apparatus for supporting the photosensitive medium, etc.

8 Claims, 61 Drawing Figures PATENWWPR w I914 $04,512

D lemma) m suse) 1072 mndlmz PATENTEMPR 1 s new sum m 0F 33 PATEN'IIEDIAPR 16 I974 180mm 2 IVISI IVIS2 IVIS8O I I L STANDARD VALUE X YSET VALUE Y TONER SUPPLIER ACTS TONER SUPPLER STOPS CAUTION ACTS CAUTION STOPS CONCENTRATION LIQ. DEVELOPER PMWEWR 18 m4 3.80%512 mm mm? m 

1. In a copying apparatus having an original carriage, means for reciprocating said original carriage, a photosensitive medium, an optical system for projecting an original image on said photosensitive medium, means for forming an image on said photosensitive medium, developing means, transfer means, means for feeding transfer mediums, means for conveying transfer mediums from said feed means to a discharge port, fixing means, and a housing for accommodating therein all of said means, comprising the improvement wherein said original carriage includes sheet original transport means integral therewith and having rollers for advancing a sheet original until the leading edge thereof reaches a detecting position, and means for temporarily stopping said sheet original at said position; said apparatus further comprising means for automatically reciprocating said original carriage, means for releasably locking said carriage against reciprocating movement, and means for generating a start signal coupled to said original carriage for initiating reciprocal movement of said carriage upon release thereof when a thick original is to be copied, and for energizing said rollers to further advance said sheet original from said detecting position when a sheet original is to be copied.
 2. A copying apparatus according to claim 1, wherein said housing and said original carriage respectively have stationary rails and movable rails extending longitudinally thereof and disposed in vertically opposed relationship with each other, said housing and said original carriage being connected together so as to define two sets of horizontally adjacent, partitioned spaces, one of said sets of spaces receiving therein horizontal and vertical rollers with retainers so as to restrain the freedom of horizontal and vertical movement of said housing and said original carriage, the other set of spaces receiving therein vertical rollers with retainers so as to restrain the freedom of vertical movement of said housing and said original carriage, thereby providing a guide mechanism for said original carriage.
 3. A copying apparatus according to claim 2, wherein said horizontal and vertical rollers with retainers in one of the spaces of said one set and said vertical rollers with retainers in one of the spaces of said other set are resilient rollers slightly larger than predetermined dimensions of said spaces in the directions for restraining said freedom of movement.
 4. A copying apparatus according to claim 2, wherein said stationary and movable rails are formed of light alloy extrudate and said horizontal and vertical rollers are formed of synthetic resin.
 5. Copying apparatus as set forth in claim 1, further coMprising means for moving said photosensitive medium upon movement of said sheet original transport rollers, and means for initiating said start signal when said carriage is disposed at said detecting position.
 6. A copying apparatus according to claim 5, wherein if said original is of such a size that a plurality of copies can be provided for one rotation of said photosensitive medium, the detection, temporal stoppage and re-start of said original may be effected in accordance with successive start signals from said photosensitive medium.
 7. A copying apparatus according to claim 5, wherein a signal corresponding to the size of said original is produced from a cam of said carriage and a microswitch of the apparatus body in response to the advancement of said original carriage to thereby control the distance of advancement of said carriage and rapidly return said carriage to the start position thereof.
 8. A copying apparatus according to claim 5, further including means for detecting a cassette inserted into said housing, said cassette containing therein transfer mediums, and means for determining the size of said cassette, whereby copying operation is automatically effected in accordance with the size of said transfer medium. 